1. Field of the Invention
The present invention relates to a capsule-type medical apparatus, which is introduced into an inside of an internal organ of a subject such as a patient to acquire in-vivo information of the subject, and a method of manufacturing such a capsule-type medical apparatus.
2. Description of the Related Art
Conventionally, a swallowable capsule endoscope having an imaging function and a radio communication function appears in the field of endoscope. The capsule endoscope is introduced into an internal organ of a subject such as a patient for an observation (examination) of an inside of the internal organ. For example, the subject swallows the capsule endoscope from the mouth. Thereafter, the capsule endoscope moves through inside the internal organs following peristaltic movements and the like while sequentially picking up an image of the inside of the subject (hereinafter may referred to as “intra-body image”) at a predetermined interval, for example, at an interval of 0.5 second. Eventually, the capsule endoscope is naturally excreted outside the body of the subject.
While the capsule endoscope is in the internal organs of the subject, the intra-body images picked up by the capsule endoscope are sequentially transmitted from the capsule endoscope to a receiver outside the body by radio communication. The subject carries the receiver, and the receiver receives the intra-body images radio transmitted from the capsule endoscope introduced inside the internal organs of the subject and stores the received intra-body images in a recording medium.
The intra-body images stored in the recording medium of the receiver are taken into an image display device such as workstation. The image display device displays the intra-body images of the subject acquired via the recording medium. Doctors, nurses, and the like can make diagnosis of the subject by observing the intra-body images displayed by the image display device.
The capsule endoscope as described above has a capsule-like casing including a transparent optical dome and a cylindrical trunk member having an open end where the transparent optical dome is attached. Inside the capsule-like casing, an illuminating unit such as an LED (light emitting diode) illuminating the inside of the internal organ through the optical dome, an optical unit such as a lens that collects light reflected from the inside of the internal organ illuminated by the illuminating unit, and an imaging unit such as a CCD (charge-coupled device) that picks up an image of the inside of the internal organ (i.e., intra-body image) formed by the optical unit are provided (see, for example, Japanese Patent Application Laid-Open No. 2005-198964, and Japanese Patent Application Laid-Open No. 2005-204924).
The optical dome of the capsule-like casing mentioned above includes a cylindrical portion fitted to the open end of the cylindrical trunk member and a dome portion having a dome-like shape. Illuminating light emitted from the illuminating unit inside the capsule-like casing passes through the dome portion to illuminate the inside of the internal organ, whereas reflected light from the inside of the internal organ thus illuminated passes through the dome portion and reaches the optical unit. Hence, mirror finish is applied to an outer wall surface and inner wall surface of the dome portion which transmits the illuminating light and the reflected light. A mold employed for molding the optical dome is divided into a mold part for molding the dome portion for which the mirror finish is required, and a mold part for molding the cylindrical portion. When the mold for the optical dome is divided into a dome-portion-side mold part and a cylindrical-portion-side mold part, the mirror finish of a semi-spherical concave surface (concave surface for forming the outer wall surface of the dome portion) of the dome-portion-side mold part can be performed easily.
However, when the optical dome is molded by the mold as mentioned above, burrs are often formed on the outer wall surface of the optical dome along a boundary line (hereinafter referred to as “parting line”) between the dome-portion-side mold part and the cylindrical-portion-side mold part. When the optical dome on whose outer wall surface such a burr is formed is employed in the capsule endoscope, the burr of the optical dome comes into contact with a living body such as an inner wall of the internal organ during the travel of the capsule endoscope in the internal organ of the subject.